Hi all!
I've been in the process of learning TIG for about a year and a half now and usually do pretty well. This week, I've been trying to make an aluminum box, but I'm having inconsistent results with the outside corner welds. Some beads will look great, and other times the aluminum melts on both pieces, blowing through and splitting them apart. Sometimes this even happens while trying to tack the parts. The will happen just a few minutes after completing a couple beads that were fine, often on the same edge after repositioning, without changing the settings.
The box I'm making is 1/16" aluminum. Everything has been thoroughly cleaned. The pieces are fitted together as well as possible (no gaps). I've tried using 1/16 and 3/32, 2% lanthanated tungsten. Tried without filler rod, and also with .045 and 1/16 filler (4043).
Machine is a Primeweld TIG225x. I've tried changing these settings within these ranges: 90-125A, both with and without pulse, AC, freq 90-120, balance 30-35, argon flow rate 12-20 cfh (checked at the torch). Ground is a few inches from the work piece.
Any suggestions would be appreciated. This is driving me crazy!
Update: I just tried to use .125" aluminum and it does the some thing, but only occasionally along the bead. Using pulse seems to help a little, but it still happened a few times along the bead. Tried 100A and 125A.
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- Using this type of corner joint.
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- This is along one edge. The other end, just a few inches away, looks fine. I stopped for a moment to reposition the piece. When I restarted, this happened.
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When it burns back like that you are either too long of an arc length, or too low on amps. Crank the amperage and use the pedal and filler wire to “cool” the puddle.
Also, your corner joint geometry is making this harder because one side is an edge, the other a flat butt joint. It’s better to have the two pieces meet and leave a split overhang (50% of the vertical edge exposed, 50% of the horizontal edge exposed) to create a true fillet weld. This will allow you to use consistent amperage across both pieces and get a stronger joint and a better weld.
Balance and frequency are fine, though I prefer 150Hz for corner fillets. I’ve spent the past 4 days making fuel tanks from 1/4” aluminum and other than the amperage difference (240 amps and pulse) this is exactly what I’ve done.
Also, your corner joint geometry is making this harder because one side is an edge, the other a flat butt joint. It’s better to have the two pieces meet and leave a split overhang (50% of the vertical edge exposed, 50% of the horizontal edge exposed) to create a true fillet weld. This will allow you to use consistent amperage across both pieces and get a stronger joint and a better weld.
Balance and frequency are fine, though I prefer 150Hz for corner fillets. I’ve spent the past 4 days making fuel tanks from 1/4” aluminum and other than the amperage difference (240 amps and pulse) this is exactly what I’ve done.
Well, I'm a total beginner, so I can't give much advice.
I just happened to post about an aluminum cube I welded yesterday. You can see a pic in my thread, and I'll post up details later tonight.
Just wanted to say that I'm having pretty good results, sticking to 1 amp per .001" of metal thickness. So, I would be around 63 amps for the 1/16" aluminum.
For tacking, sometimes I have the same issue. So, I usually heat the metal a bit, then mash the pedal- just until I see flow, then off. Sometimes, I add a dab of rod at that moment.
By keeping the amps at that setting, I don't burn through when I mash the pedal, unless the fit-up is poor.
Good luck, brother.
I just happened to post about an aluminum cube I welded yesterday. You can see a pic in my thread, and I'll post up details later tonight.
Just wanted to say that I'm having pretty good results, sticking to 1 amp per .001" of metal thickness. So, I would be around 63 amps for the 1/16" aluminum.
For tacking, sometimes I have the same issue. So, I usually heat the metal a bit, then mash the pedal- just until I see flow, then off. Sometimes, I add a dab of rod at that moment.
By keeping the amps at that setting, I don't burn through when I mash the pedal, unless the fit-up is poor.
Good luck, brother.
that type of corner joint is really a butt joint next to an edge.
what i suspect your trying to do is melt the whole corner into a bead which is not a good way.
if you melt the corner the actual joint is to the side which will be colder and will pull away.
there is also a weird porosity issue you can get with butt welds and i suspect it will be worse in that config.
aluminium is best where the joint is open so the arc can get in and clean the surfaces.
what i suspect your trying to do is melt the whole corner into a bead which is not a good way.
if you melt the corner the actual joint is to the side which will be colder and will pull away.
there is also a weird porosity issue you can get with butt welds and i suspect it will be worse in that config.
aluminium is best where the joint is open so the arc can get in and clean the surfaces.
tweak it until it breaks
Thank you! Tightening up the arc and increasing amps by 20A made a world of difference! I'll keep your advice in mind in the future for setting up corner joints. This particular piece needed to be slightly narrower in one dimension than the other. I should have just taken the time to cut the pieces down a little more. The beads look a lot better now. Not perfect, but good for this application. Again, thanks!
cj737 wrote: ↑Sun Apr 03, 2022 3:59 pm When it burns back like that you are either too long of an arc length, or too low on amps. Crank the amperage and use the pedal and filler wire to “cool” the puddle.
Also, your corner joint geometry is making this harder because one side is an edge, the other a flat butt joint. It’s better to have the two pieces meet and leave a split overhang (50% of the vertical edge exposed, 50% of the horizontal edge exposed) to create a true fillet weld. This will allow you to use consistent amperage across both pieces and get a stronger joint and a better weld.
Balance and frequency are fine, though I prefer 150Hz for corner fillets. I’ve spent the past 4 days making fuel tanks from 1/4” aluminum and other than the amperage difference (240 amps and pulse) this is exactly what I’ve done.
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Last edited by Spectre on Mon Apr 04, 2022 8:12 pm, edited 2 times in total.
Haha! Yeah, I really haven't had many problems since I bought the machine that I haven't been able to figure out. It's nice having a resource for situations like this, though.
Thank you! Every bit of advice helps.
Kodokan wrote: ↑Sun Apr 03, 2022 7:05 pm Well, I'm a total beginner, so I can't give much advice.
I just happened to post about an aluminum cube I welded yesterday. You can see a pic in my thread, and I'll post up details later tonight.
Just wanted to say that I'm having pretty good results, sticking to 1 amp per .001" of metal thickness. So, I would be around 63 amps for the 1/16" aluminum.
For tacking, sometimes I have the same issue. So, I usually heat the metal a bit, then mash the pedal- just until I see flow, then off. Sometimes, I add a dab of rod at that moment.
By keeping the amps at that setting, I don't burn through when I mash the pedal, unless the fit-up is poor.
Good luck, brother.
A final thought on welding aluminum, Spectre. Whenever possible, preheat the material along the weld line with Propane or MAPP gas to push the moisture out of the material, especially along edges like this. That moisture can create an undue amount of porosity in the weld and aluminum welds don’t tend to be very strong to begin with.
For thicker material, I use Oxy/Acetylene to get it hot, around 200*-300*. It makes a world of difference in the weld, the amount of heat needed to get a puddle, and the fluidity of the puddle.
For thicker material, I use Oxy/Acetylene to get it hot, around 200*-300*. It makes a world of difference in the weld, the amount of heat needed to get a puddle, and the fluidity of the puddle.
Got it! Thanks!
cj737 wrote: ↑Tue Apr 05, 2022 8:55 am A final thought on welding aluminum, Spectre. Whenever possible, preheat the material along the weld line with Propane or MAPP gas to push the moisture out of the material, especially along edges like this. That moisture can create an undue amount of porosity in the weld and aluminum welds don’t tend to be very strong to begin with.
For thicker material, I use Oxy/Acetylene to get it hot, around 200*-300*. It makes a world of difference in the weld, the amount of heat needed to get a puddle, and the fluidity of the puddle.
is it still April 1st?cj737 wrote: ↑Tue Apr 05, 2022 8:55 am A final thought on welding aluminum, Spectre. Whenever possible, preheat the material along the weld line with Propane or MAPP gas to push the moisture out of the material, especially along edges like this. That moisture can create an undue amount of porosity in the weld and aluminum welds don’t tend to be very strong to begin with.
For thicker material, I use Oxy/Acetylene to get it hot, around 200*-300*. It makes a world of difference in the weld, the amount of heat needed to get a puddle, and the fluidity of the puddle.
the "moisture" is a myth, its only condensation.
aluminium that thin does not need preheat. in fact it can make things worse as you can overheat your material quicker.
preheat is handy when your pushing the limits of your welder, typically with thick material.
tweak it until it breaks
Joke’s on you, Tweake. Condensation IS MOISTURE. Whether you describe it as condensation or moisture it is still water.
200* preheat on 1/8” won’t hurt a thing, but I do concur that it is possible to overheat aluminum which can cause more problems. And I did characterize my counsel with “whenever possible”.
200* preheat on 1/8” won’t hurt a thing, but I do concur that it is possible to overheat aluminum which can cause more problems. And I did characterize my counsel with “whenever possible”.
cj737 wrote: ↑Wed Apr 06, 2022 8:06 am Joke’s on you, Tweake. Condensation IS MOISTURE. Whether you describe it as condensation or moisture it is still water.
200* preheat on 1/8” won’t hurt a thing, but I do concur that it is possible to overheat aluminum which can cause more problems. And I did characterize my counsel with “whenever possible”.
the moisture comes from the burning fuel, not from the material. your not "push(ing) the moisture out of the material", thats complete nonsense.
the material in question is 1/16.
with the 200+ amp machine hes using even 1/8 does not need pre heat and can cause overheating. i've overheated 1/8 doing long welds before.
the one time it can come in real handy is doing some of the thick joints where it tends to act like its 1/4 thick. a preheat especially at the start helps.
so to tie back into the original question, joint configuration and what order you weld, makes a big difference. making better fit up makes the welding a whole lot easier.
tweak it until it breaks
On the topic of moisture/ condensation.
My uneducated opinion on it is.
Depends on your ambient start temp and your ambient humidity.
Parts in the shop always behave different between summer and winter.
I find that if I'm heating a part up in the winter it takes longer to 'truly' dry.
Looks dry to the naked eye then you throw the torch on it and it's still dry for a second or two them BAM it's moist right around the flame and the moisture follows the flame. And this is for bare sandblasted steel or aluminum that was already dried before going in the blast cabinet.
Seems to be less exaggerated in the summer when humidity in the shop is lower.
My best guess is it's not necessarily moisture on/in the part but more so moisture in the air being attracted to the now hotter than ambient air.
I'll hazard a guess that when I strike a arc the moisture is drawn to the heated metal but dried from the heat of the arc.
Beats me though as I've never had high def vids done for my welds where you'd maybe be able to see that type of detail while you can focus solely on it.
Just figured I'd throw that out there.
My uneducated opinion on it is.
Depends on your ambient start temp and your ambient humidity.
Parts in the shop always behave different between summer and winter.
I find that if I'm heating a part up in the winter it takes longer to 'truly' dry.
Looks dry to the naked eye then you throw the torch on it and it's still dry for a second or two them BAM it's moist right around the flame and the moisture follows the flame. And this is for bare sandblasted steel or aluminum that was already dried before going in the blast cabinet.
Seems to be less exaggerated in the summer when humidity in the shop is lower.
My best guess is it's not necessarily moisture on/in the part but more so moisture in the air being attracted to the now hotter than ambient air.
I'll hazard a guess that when I strike a arc the moisture is drawn to the heated metal but dried from the heat of the arc.
Beats me though as I've never had high def vids done for my welds where you'd maybe be able to see that type of detail while you can focus solely on it.
Just figured I'd throw that out there.
Jack Ryan
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There tends to be some (wider) disagreement in this area but here is my 2c worth.
Most seem to agree that hydrogen is a major source of porosity, and that hydrogen comes from several sources including hydrocarbon contamination and water. The question is, where does the water come from?
There are books, papers and manufacturer’s information on the subject - some of the sources are:
Neither aluminium nor aluminium oxide (alumina) is porous and can absorb water. Unfortunately, the oxidation of aluminium at room temperature and in an unclean/moist environment leads to the formation of some hydrated alumina both on base metal and on filler material.
TIG welding with the proper cleaning action (balance) is sufficient to weld with uncontaminated (not hydrated) alumina but (stainless steel) wire brushing is recommended to remove contaminated alumina before welding.
Jack
Most seem to agree that hydrogen is a major source of porosity, and that hydrogen comes from several sources including hydrocarbon contamination and water. The question is, where does the water come from?
There are books, papers and manufacturer’s information on the subject - some of the sources are:
- Leaking water-cooled torches
- Condensation from both gas preheating and the atmosphere during welding
- Hydrated aluminium oxide on base metal and filler rods
Neither aluminium nor aluminium oxide (alumina) is porous and can absorb water. Unfortunately, the oxidation of aluminium at room temperature and in an unclean/moist environment leads to the formation of some hydrated alumina both on base metal and on filler material.
TIG welding with the proper cleaning action (balance) is sufficient to weld with uncontaminated (not hydrated) alumina but (stainless steel) wire brushing is recommended to remove contaminated alumina before welding.
Jack
i think what people forget is burning fuel generates water as a byproduct. so what comes out of the flame is actually moisture.Toggatug wrote: ↑Mon Apr 11, 2022 7:49 pm On the topic of moisture/ condensation.
My uneducated opinion on it is.
Depends on your ambient start temp and your ambient humidity.
Parts in the shop always behave different between summer and winter.
I find that if I'm heating a part up in the winter it takes longer to 'truly' dry.
Looks dry to the naked eye then you throw the torch on it and it's still dry for a second or two them BAM it's moist right around the flame and the moisture follows the flame. And this is for bare sandblasted steel or aluminum that was already dried before going in the blast cabinet.
Seems to be less exaggerated in the summer when humidity in the shop is lower.
My best guess is it's not necessarily moisture on/in the part but more so moisture in the air being attracted to the now hotter than ambient air.
I'll hazard a guess that when I strike a arc the moisture is drawn to the heated metal but dried from the heat of the arc.
Beats me though as I've never had high def vids done for my welds where you'd maybe be able to see that type of detail while you can focus solely on it.
Just figured I'd throw that out there.
this is why we do not use fuel burners to dry houses out during construction, it makes the house damp not dry.
so its the super humid area just in front of the flame that condenses on cold metal, which makes it look like metal holds moisture.
when the metal gets hot enough the moistures doesn't condense. as its colder in winter it takes longer to heat the metal up to where it doesn't condense.
tweak it until it breaks
Ah! Lol, I think I was looking at your join date vs the thread post date... Then I didn't stop back to the thread again. Oh well, I'll just claim I was drunk when I posted that. Mathematically, that's likely!
